Reverse current trip circuit breaker



July 24, 1951 Filed May 50, 1948 WITNESSES:

C. L. JONES ET AL REVERSE CURRENT TRIP CIRCUIT BREAKER 3 Sheets-Sheet 1 INVENTOR$ Char/es L .J'anes an \ir'ame fiafld/h.

ATTORNEY y 24, 1951 c. 1.. JONES ETAL REVERSE CURRENT TRIP CIRCUIT BREAKER 3 Sheets-Sheet 2 Filed May 30. 1948 d. 7 9a 7 7 3 7m Mme wig m w QM m m M; Y O? E 11% 9 m 9 m Mia m w w 9 15 il/ 3 a wW W M 7 Z a M M 2 aw w c 9 lllll fl 5 M l H 3 L1! d 5 .m 7 4 M v 7 3/ w GU88 n 9 WITNESSES: 1 .2. 5&W/ 77 Patented July 24, 1951 UNITED STATES PATENT OFFICE 7 REVERSE CURRENT TRII CIRCUIT BREAKER Charles L. Jones, Beaver, and Jerome Sandin, Pittsburgh, Pa., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., :1 corporation of Pennsylvania Application April 30, 1948, Serial No. 24,318

1: Claims. (Cl. 175-294) This invention relates to circuit breakers, and more particularly to circuit breakers embodying electromagnetic tripping means for trippin the breaker in response to predetermined circuit conditions.

An object of the invention is to provide an enclosed multipole circuit interrupter with a reverse current relay which is mounted in one compartment of the casing where it is protected from damage and its line parts are enclosed, but is still easily accessible for inspection or replacement.

Another object of the invention is to provide a multipole circuit interrupter having main contact means with an improved reverse current relay which is provided with a potential coil, a solenoid energized upon operation of the relay in response to a reversal of current in the circuit interrupter to eflect opening of the main contact means, the opening movement of the main contact means actuating a switch to effect deenergization of the potential coil.

Another object of the invention is to provide a two-pole circuit interrupter having a casing divided into three pole compartments, two of which are for receiving separable contact means and wherein an improved electroresponsive trip device is mounted in the third compartment in place of a third pole of the interrupter.

Another object of the invention is to provide a circuit interrupter with an improved reverse current relay having a normally energized holding coil and a solenoid energized upon operation of said relay to effect tripping of the interrupter in which the holding coil and the solenoid are energized from separate sources of energy.

The novel features that are considered characteristic of the invention are set forth in particular in the appended claims. The invention itself, however both as to structure and operation. together with additional advantages thereof will best be understood from the following detailed description thereof when read in conjunction with the accompanying drawings.

In said drawings:

Figure 1 is a top plan view of a circuit breaker embodying the principles of the invention, the cover being partly broken away to more clearly show the parts,

Fig. 2 is a vertical sectional view of the circuit v breaker taken substantially on line 11-11 of Fig. l.

Fix. 3 is a vertical sectional view taken on line 111-111 of Fig. 1 showing the reverse current trip device mounted in position in the breaker housins.

Fig. 4' is an enlarged top plan view of the reverse current trip device,

Fig. 5 is an enlarged sectional view taken on line V-V of Fig. 4 showing the reverse current trip device,

Figs. 6 and 7 are wiring diagrams of circuits for controlling the tripping of the breaker by the reverse current relay.

Referring to Figs. 1 and 2 of the drawings, the circuit breaker is of the multiple type and comprises a base 1 of molded insulating material suitably divided into three compartments, a cover I also of molded insulating material suitably secured to the base, operating mechanism indicated generally at I i, an overload trip device indicated generally at I! having a separate electroresponsive tripping means for each of two poles of the breaker, a shunt trip device I! and a reverse current relay indicated generally at I4. Each pole of the breaker is provided with a stationary contact i5 mounted on the lower end of a conductor H of the corresponding pole of the breaker, the conductor being suitably secured to the base 1 of the breaker.

The base I of the breaker is divided into three compartments by means of partition walls 31 molded integral with the base, and corresponding walls 39 molded integral with the cover 9.

The movable contact structures for the two poles of the breaker are alike; therefore, only the structure for the right-hand pole (Fig. 1) which is disposed in the center compartment will be described. A movable contact i9 is secured to a contact arm 2| which is loosely supported on a channel-shaped switch arm 23. The channelshaped switch arms for the two poles are rigidly secured together for unitary movement by means oi a tie bar 25 which extends transversely across all of the poles of the breaker. The tie bar 25 is secured to the switch arms 23 adjacent the pivoted ends thereof by means of metal clamps 21. An insulating tube 29 surrounds the tie bar in order to insulate the poles of the breaker. The channel-shaped switch arm 23 for the right-hand pole is pivotally supported on a pin 3| mounted in a U-shaped main frame 33 secured to the base I of the breaker by means of screws 35.

The upper end of a flexible conductor is connected to the lower end of the contact arm II and the lower end of the flexible conductor is connected by means of a screw 49 to a conductor ii which forms the energizing means for the corresponding pole of the trip device II. The conductor II has its lower end connected to a terminal It. The upper end of the conductor I] is similarly connected to a terminal connector. The circuit for each pole extends from the upper terminal ll. to the conductor ll, stationary and movable contacts |5il, contact arm 2i, flexible conductor ll, and the energizing conductor ii to the lower terminal 88. The movable contacts of the two, poles of the breaker are adapted to be operated to open and closed positions to open and close the circuit through the breaker by the single operating mechanism ii. The operating mechanism comprises a releasable carrier or support member is pivotally mounted by means of a pin I on the main frame II, a pair of toggle links 63 and O5 interconnecting the carrier 58 and the switch arm 13 for the right-hand pole. a U-shaped operating lever 81. overcenter springs 69 connecting the operating lever and the knee pivot pin II of the toggle links and an insulating operating handle II for manually operating the lever 01.

The toggle link 63 is pivotally connected to the carrier 50 by means 0! a pin I! and the toggle link II is similarly connected to the switch arm 23 for the right hand pole by means of a pin 11. The two legs of the operating lever G1 are disposed adjacent the inner sides of the main frame a and are pivotally supported on pins 19 proiecting inwardly from the sides of the frame. The operating handle 13 projects outwardly through an opening CI in the cover I and is provided with an areuate protective portion '3 having side portions l5 integral with the portions ll. The operating handle II is secured to the operating lever 61 by means of screws 01. The yoke portion of the operating lever 81 is provided with a formed over portion I! for the purpose oi engaging and resetting the carrier 5! following a tripping operation of the breaker. The carrier I9 is normally restrained in latched'positlon (Fig. 2) by a latch SI of the trip device, which engages a latching portion it of the carrier.

With the parts in the position shown in Fig. 1. the circuit breaker is manually operated to the "open" position by movement of the operating handle II and the operating lever 61 in a clockwise direction. During this clockwise rotation the line of action of the overcenter springs 69 moves below the pin and causes the toggle links "-45 to collapse, thereby causing movement of the switch arms 23 and the movable contacts I! to the open-circuit position with a snap action. The breaker is closed by movement of theoperating handle 13 in the opposite direction to the Fig. lposition, during which movement the overcenter springs 69 move above the pivot.

pin ll and move the toggle 63-65 to the ln-toggle position to close the contact means with a snap action.

The circuit breaker is opened automatically, in response to an overload current occurring in the circuit of either pole of the breaker by operation of the trip device I! which releases the latch 9|. Release of the latch 9| frees the carrier 59 and permits the overcenter springs to rotate the carrier in a counterclockwise direction, thus causing collapse or the toggle 6365 and movement of the switch arms to the open-circuit position. Following an automatic tripping operation, the breaker is reset and the contacts closed by first moving the operating handle 18 to the full open position to reset and relatch the carrier II with the latch Ii, and then moving the handle ii to the closed position to eflect closing of the contacts.

The trip device comprises an insulating base or support member 95 (Fig. 2) suitably secured to an angle bracket 98 which, in turn, is secured to the base I of the breaker by means of the screws Q9. The trip device is enclosed by a cover I" of insulating material. The energizing conductor ii for each pole has a loop Nil-thereon which embraces the yoke ill of a U-shaped magnet core III which is suitably secured by means of bolts It! to the base 95 of the trip device. The bolts I01 extend through the pole pieces of the magnet core I05 and serve to slidably support on their lower ends an armature I09 which is biased to unattracted position by means of coil springs (not shown) surrounding the bolts ill between the armature and the pole faces. The armature is supported in place by nuts on the lower ends of the bolts I01.

A trip bar Ill, pivotally mounted on the base of the trip device by pivot means (not shown) extends across all of the poles of the breaker. There is secured to the trip bar I II a member Iii for each of the poles of the breaker, which member extends above the associated armature I to be operated thereby.

The latch ll is pivotally mounted on a pin lil supported in the brackets 99, and is biased in a counterclockwise direction b means of a spring (not shown). The lower end N9 of the latch member 9| comprises a latch surface which ensages a latch roller III mounted on a bracket m secured to the trip bar H3.

Upon the occurrence of an overload current in the circuit through either pole of the breaker. the

the corresponding member He and rotates the trip bar 3 in a clockwise direction as viewed in Fig. 2. Clockwise rotation of the trip bar Ill moves the latch roller III out of engagement with the latch surface lie of the latch member II. The carrier member 59 is biased in a counterclockwise direction about its pivot I by the overcenter springs 68 so that when the latch member ii is released. the carrier rotates the latch member sl clockwise until the latching end 93 of the carrier 59 is free of the latch member 9!. When the carrier 59 is thus released. the toggle tl-ll collapses and the movable contacts are moved to open circuit position. The breaker cannot be reclosed until the handle ll has been moved to the full open position to reset and latch the carrier member. After the carrier 58 has been reset and latched, the operating handle may be moved to the closed position to effect closing of the contact means.

The reverse current relay I4 is disposed in the right-hand compartment of the base as shown in Fig. 1, and comprises a pair of spaced parallel U-shaped pole members I25 having an iron core I21 (Fig. 5) disposed therebetween adjacent one end. The core I21 is secured to the pole members I25 by means of screws I28 and has an insulating tube Ill surrounding it upon which is mounted a potential coil I33. Secured to the ends of the upper legs of the U-shaped pole members "I is a T-shaped bracket I35 of non-magnetic material which has a downward extending leg I" (more clearly shown in Fig. 5) for supporting a laminated armature I39. The armature I3! is pivotally mounted on a pivot stud I supported in the leg ill and extending inwardly therefrom. The upper and lower legs of each of the pole members I28 are provided with pole faces III (Figs. 1, 4 and 5) for cooperating with the armaaccuses ture I39. The pole faces I39 are rigidly secured to the legs of the pole pieces adjacent the armature. Surrounding the armature I39 is an insulating tube HI and a series coil I43 surrounds the tube I4 I. Insulating washers I45 are disposed adjacent the ends of the tube I4I between the series coll I43 and the legs of the pole members I25 to insulate the coil from the pole members.

The laminations of the armature are secured together by means of rivets I41, the upper two of which (Fig. 5) serve also to secure an angular bracket I49 to the armature adjacent the upper end thereof. One angle I5I of the bracket I49 extends to the right (Figs. 4 and 5) and carries a spring wire bridging contact I59 secured to the angle III by means of a rivet I55. Upon operation of the armature I39, the bridging contact I53 is adapted to bridge a pair of spaced stationary contacts I51 secured by means of screws I59 to an insulating plate IIiI. The plate IN is mounted on the pole members I25 and is secured thereto by means of long screws I63 (Fig. 3) which extend through openings in the ends of the plate I6I and through openings in the pole members and threadedly engage metal inserts I95 molded in the base 1 of the breaker to rigidly secure the reverse current relay thereto.

The armature I39 is biased by means of a spring I51 against an adjustable limit stop screw I59 threadedly mounted in one of the pole members I25 as shown in Fig. 4 of the drawings. The ends of the spring I61 are hooked over spring studs IH and I13, respectively, mounted in the end of the armature and in one of the pole members I25.

Referring particularly to Fig. l of the drawings, one end I15 of the series coil I43 is connected to a terminal connector I11 (see also Fig. 3) and the other end I19 is connected by means of a conductor I8I to the terminal connector 53 (see also Fig. 2) for the center pole of the breaker. An opening I92 is provided in the partition wall 39 of the cover to accommodate the conductor Ill. The lower terminal 53 (Fig. 2) for the center pole of the breaker is connected by means of a conductor I83 to the lower terminal I (Figs. 1 and 3) for the right-hand pole. The circuit through the reverse current relay I4 and the center pole of the breaker extends as follows: From the terminal connector I11 (Figs. 1 and 3) through the series coil I43, conductor I9I, terminal 53 for the right-hand pole, conductor I1 (Fig.

2), stationary and movable contacts I5I9, contact arm 2I, flexible conductor 45, overload energizing loop IOI, lower terminal 53 for the center pole and conductor I33 to the lower terminal I95 (Figs. 1 and 3) of the right-hand pole.

With normal rated current flowing in the proper direction through the circuit dust described, the overload trip device will not function to trip the breaker and the armature I39 of the reverse current relay I4 will be attracted in a direction to maintain the bridging contact I53 in the open position as clearly shown in Fig. 4. The occurrence of an overload current in the circuit will cause the overload trip device I3 to function and trip the breaker in the previously described manner but will not affect the reverse current relay. Should a reversal of the direction of current flow occur, the armature I39 of the reverse current relay will be actuated to close the contacts I53I51 and energize the shunt trip device I2 over the circuit shown in Figs. 6 or '7 to trip the breaker.

The shunt trip device I2 (Figs. 1 and 3) comprises a solenoid I31 mounted on a bracket I89 secured to the base 35 of the overload trip device. The solenoid is provided with a movable core (not shown) having a plunger I9I attached thereto. The lower end of the plunger I9I is enlarged as at I93 and extends into a clearance opening I95 provided therefor in the base 95 of the trip device. The plunger III is adapted upon energization oi the solenoid to engage and operate the trip bar II3 of the trip device. I

Mounted on the upper end of the solenoid I31 Figs. 1 'and 3) is'an insulating bracket I91 in which is rigidly secured a pair of spaced stationary contacts I99. A bridging contact 20I is loosely mounted adjacent the end of a rod 203 which is slidably supported in the bracket I91. The outer end of the rod 203 has an enlarged head as at 205 and the rod 203 is biased in a direction to engage the bridging contact by means of a coil spring 201 surrounding the rod 203 and compressed between the bracket I91 and the head 205 of the rod.

The contacts I99-20I are closed when the circuit breaker is closed but are adapted to be opened upon opening of the movable contacts of the circuit breaker by means of a channel-shaped arm 209. The arm209 is secured to the tie bar 25 in the same manner as the channel-shaped switch arm 23 as shown in Fig. 2, that is, by means of clamps 21, and is insulated therefrom by the insulating tube 29.

Referring now to Fig. 6 of the drawings, the potential coil I33 is normally energized from a separate source over a circuit extending from a source conductor 2I I, the potential coil I33, contacts I9920I (closed when the breaker is closed) to a source conductor 2I3. As long as the potential coil is energized and current of predetermined value is flowing in a predetermined direction through the series coil I43 and the circuit of the right-hand pole of the breaker, the armature I39 of the reverse current relay I4 will be held in a position to maintain the contacts I53I51 open. If the direction of flow of the current through the series coil I43 of the reverse current relay is reversed, the "polarity of the armature I39 is reversed, in whichcase the armature is actuated in a direction to close the contacts I53I51 and energize the shunt trip solenoid I91 over a circuit extending from the source conductor 2| I, contacts I53-I51, the'coil of the solenoid I91 to the source conductor 2I3.

Energization of the solenoid I31 causes actuation of the plunger I9I which engages and operates the trip bar II3 to release the latch 9i and thereby eifect automatic opening of the-breaker contacts. As the breaker contacts move to the open position, the arm 209 (Fig. 3) engagestherod 253 and moves it to eflect opening of the contacts I99-20I which opens the circuit through the potential coil I33.

This permits the spring I91 (Figs. 1 and 4) to move the armature I39 back to its normal position opening the contacts I53I51 which deenergizes the solenoid I91. The breaker may now be reset and the contacts closed in the previously described manner.

A manually operable switch 2I5 may be provided if desired for closing contacts 2I1 which are connected in the circuit in parallel to the contacts I51. Operation of the switch 2I5, which may be located remotely from the circuit breaker,

- energizes the shunt trip solenoid .to effect tripping the breaker open from a point remote from the breaker.

It will be observed that in the embodiment shown in m. 6, both the potential @611 m and the shunt trip coil I81 are arranged to be energized from a single source over the conductors 2| l-Ill. In some instances, it is preferable to energize the potential coil and the shunt trip device from separate sources. Accordingly, in the embodiment illustrated in Fig. 7, separate circuits are provided for the potential coil and the shunt tripping solenoid. The circuit for the potential coil It: comprises source conductors Ill and Iii and extends from the conductor 2", through the potential coil iii, the contacts lll2lll to the source conductor HI. Similarly, the circuit for the solenoid I81 extends from a source conductor 223 through the contacts iii-Ill and the solenoid III to a source conductor 225. The operation of the embodiment of Fig.7 is the same as that described in connection with Fig. 6.

While the invention has been disclosed in accordance with the provisions of the patent statutes, it is to be understood that various changes in the structural details thereof may be made without departing from the spirit of the invention.

We claim as our invention 1. A multipole circuit interrupter comprising a casing section of one piece molded insulating material divided into a plurality of compartments extending longitudinally of said casing, a trip member extending transversely of said casing across all of said compartments and operable to eiiect automatic opening of said interrupter, support means for said trip member secured to said casing and forming a separate isolated compartment extending transversely of said casing, a

, trip device for at least one pole of said interrupter comprising an electromagnet mounted in said transverse compartment on said support means and operable in response to overload currents to actuate said trip member, electroresponsive means disposed in one of said longitudinal compartments and operable in response to a reversal of direction of current, a solenoid mounted in said one longitudinal compartment on said supportmeans and operable when energized to actuate said trip member, and contact means actuated by said electroresponsive means for energizing said solenoid.

2. A multipole circuit interrupter comprising a casing section of one piece molded insulating material having partition walls forming a plurality of compartments extending longitudinally of said casing, separable main contact means disposed in at least two of said longitudinal compartments, a partition wall extending transversely of said casing forming a separate isolated compartment extending transversely of said casing adjacent one end thereof, a trip bar mounted on said transverse wall in said separate compartment, said trip bar extending across all of said longitudinal compartments and operable to effect automatic opening of said contact means, a trip device disposed in said transverse compartment comprising electromagnetic means for at least two poles ofsaid interrupter operable in response to overload currents to actuate said trip bar, a solenoid disposed in the third of said longitudinal compartments operable when energized to actuate said trip bar, and electroresponsive means disposed in said third longitudinal com partment and operable in response to a reversal of thedirection of flow of current through the circuit of one of said poles to effect energization of said solenoid. I

3. A multipole circuit interrupter comprising a casing section of one piece molded insulating msterial having partition walls molded integral therewith forming three compartments extending longitudinally of said casing, separable main contact means disposed in two of said longitudinal compartments, a member of insulating material secured to said casing and extending transversely thereof to form a separate transverse'isolated compartment adjacent one end of said casing, a trip bar mounted on said transverse member disposed in said transverse compartment and extending across all of said longitudinal compartments, said trip bar being operable to effect automatic separation of said main contact means, trip means disposed in said transverse compartment and operable to actuate said trip bar in response to overload currents, electromagnetic trip means mounted on said transverse member and disposed in said third longitudinal compartment operable when energized to engage and actuate said trip bar, electroresponsive means including a normally energized potential coil disposed in said third longitudinal compartment adjacent the end of said casing opposite said transverse compartment, said electroresponsive means being operable in response to reversal of the direction of flow of current in one of the poles of the interrupter, contact means operable by said electroresponsive means for energizing said electromagnetic trip means, and auxiliary contact means operable upon separation of said main contact means to deenergize said potential coil.

4. A two-pole circuit interrupter comprising an enclosing casing having therein three compartments positioned side by side, separable main contacts and movable contact operating arms therefor in two ofsaid compartments in said enclosing casing, an operating mechanism in at least one of said two compartments connected to said contact arms for actuating said contact arms to open and close said main contacts, a reverse current operated mechanism including a current coil-positioned in the third of said compartments in said enclosing casing and connected to said operating mechanism to cause said operating mechanism to effect opening of said main contacts in the other two compartments in said enclosing casing, terminals at each of the opposite ends in two of said compartments, one terminal at one end of one compartment being connected to one end of said current coil, the other end of said current coil having a conducting strip extending into the adjacent compartment and connected to the main contact in said adjacent compartment.

5. A two-pole circuit interrupter comprising an enclosing casing having therein three compartments positioned side by side, separable main contacts and movable contacts operating arms therefor in two of said compartments inv the enclosing casing, a manual operating mechanism in at least one of the two compartments having said main contacts and said contact arms therein connected to said contact arms for actuating said contact arms to open and close said main contacts, a tripping mechanism including a current traversed element positioned in the third of said compartments in the enclosing casing and connected to said operating mechanism to cause said operating mechanism to cause opening of said main contacts in the other two compartments, terminals at each of the opposite ends in two of the compartments. one terminal at one end of said third compartment being connected to one end of said current traversed element and the other end of said current traversed element said third compartment having a conducting strip extending into the adjacent compartment and connected to said movable contact arm therein.

6. A two-pole circuit interrupter comprising an enclosing casing for a three-pole interrupter having three compartments therein positioned side by side, terminals at each of the opposite ends of two compartments, separable main con-- tacts positioned in two oi said compartments adjacent one end thereof, the main contacts in one of said two compartments being electrically connected to the terminal adjacent said one end said compartment, movable contact operating arms in said two compartments in said enclosing casing, operating mechanism positioned in one of said two compartments adjacent the midportion thereof and connected to said contact arms for actuating said contact arms to open and close said main contacts, current responsive trip means in said one compartment electrically connected to the contact arm in said one compartment and connected to said operating mechanism to cause said operating mechanism to cause opening of said main contacts in said two compartments, said current responsive trip -means being electrically connected to the other terminal in said one compartment, and a re- 1 verse current operated mechanism positioned in the third of said compartments in the enclosing casing and connected to the operating mechanism to cause said operating mechanism to cause opening of the main contacts in the other two compartments.

7. A two-pole circuit interrupter comprising a base and a cover each of insulating material forming an enclosing casing having therein three compartments positioned side by side, separable main contacts and movable contact operating arms therefor in two of said compartments in said enclosing casing, an operating mechanism in at least one 01' said two compartments connected to said contact arms for actuating said contact arms to open and close said main contacts, overload rosponsive means in each oi said two compartments and electrically connected in series with said main contacts in said two compartments and acting on said operating mechanism to cause said operating mechanism to efiect opening of said main contacts, a reverse current operated mechanism including a current coil positioned in the third of said compartments in said enclosing casing and electrically connected in series with the main contacts in one of said two compartments and said reverse current mechanism acting on said operating mechanism to cause said operating mechanism to effect opening of said main contacts in the other two compartments.

8. A multiple circuit interrupter comprising a casing of one-piece molded insulating material having partition walls forming compartments extending longitudinally of said casing, separable main contact means disposed in at least two oi. said compartments, a trip bar extendi cross said compartments and operable to effect automatic opening 01' said contact means, a trip device comprising an electromagnet for at least one pole or said interrupter disposed in one end of said casing and operable in response to overload currents to actuate said trip bar, support means for said trip device rigidly mounted on t l0 I said casing and forming a separate compartment for said trip device, said separate compartment extending transversely of said longitudinal compartments adjacent one end of said casin electroresponsive means disposed in'one 01' said longitudinal compartments adjacent the opposite end of said casing, said electroresponsive means being operable in response to reversal of the direction of flow of the current in the cir-' cuit of said one pole, and a solenoid mounted in said one longitudinal compartment on said support means for said trip device to be energized in response to operation or said electroresponsive means and operable when energized to actuate said trip bar.

9. A multipole circuit interrupter comprising a casing of one-piece molded insulating material having partitlon walls extending-substantially the length of said casing forming isolated compartments, separable main contact means disposed in at least two of said compartments, a trip member extending across said compartments and operable to efiect automatic separation of said contact means, trip means electrically connected in series relation with the main contacts in each of at least two of said compartments, said trip means being operable in response to overload currents to actuate said trip member, support means for said trip means mounted on said casing, a relay disposed in one oi said compartments and operable in response to reversal of flow of current in the circuit controlled by said interrupter, said relay comprising an energizing winding connected in series relation in the circuit controlled by one pole of the breaker, a normally energized holding coil and an armature, a solenoid mounted in said one compartment on said "support means adjacent said trip member and common to said movable contacts and extending into the third compartment, a trip member extending across all of said compartments switch means operable by said armature to e1- 7 feet energization of said solenoid, a second switch means positioned in said third compartment connected in series relation with said potential coil, and means in-said third compartment mounixed on said pivot and movable with said movable contacts in said two compartments when said contact means moves to open 2,se1,oss

said circuit to engage and open said second switch means.

11. A multipole circuit interrupter comprising a casing of molded insulating material having partition walls forming three separate compartments, main stationary contact means and cooperating movable contact means disposed in two of said compartments, a trip member disposed adiacent one end of said casing extending across said compartments and operable to eflect opening movement of said movable contact means, an electromagnetic trip device electrically connected in series relation with the main contacts in one of said two compartments and operable in response to overload currents to actuate said trip member, an electrorespom.

sive relay' disposed in the third one of said compartments, said relay being connected in series with the main contacts in said one compartment and operable in response to reversal of the direction/of current flow in the circuit controlled by said interrupter, said relay including a normally energized potential coil, an armature operable by said trip device, a solenoid disposed in said third compartment adjacent said trip member operable when energized to actuate said trip member, spring contact means mounted on said armature tor eitecting energization of said solenoid upon operation of said armature, switch means disposed in said third compartment connected in series relation with said potential coil, and means extending into said third compartment and operable upon opening movement of said movable contact means to actuate said switch means to cause deenergization of said potential coil.

12. A multipole circuit interrupter comprising a casing 01 one-piece molded insulating material having partition walls forming compartments positioned side by side, separable main contact means disposed in two 0! said compartments, a trip member extending transversely across said compartments adjacent one end of said casing and operable to eflect automatic separation of said main contact means, trip means disposed on one sideof said trip member operable in response to overload currents to actuate said trip member, electrcresponsive means including a normally energised potential coil removably mounted in one 0! said compartments adjacent the other end of said casing, a tripping solenoid removably mounted in said one compartment adjacent to but on the opposite side o! said trip member from said trip means operable when energised to actuate said trip memben'a movable armature having switch means thereon operable by said electroresponsive means in response to a reversal of direction of flow of the current in the circuit controlled by the interrupter to eflect energization of said solenoid, and auxiliary contact means in said one compartment operable upon separation of said main contact means to deenergize said potential coil.

CHARLES L. JONES.

JEROME SANDIN.

REFERENCES. CITED The following references are of record in the tile of this patent:

UNITED STATES PATENTS Number Name Date 630,539 Hewlett Aug. 8, 1999 883,943 Eveleth Apr. 7, 1908 960,970 Leonard June 7, 1910 1,149,496 Cheney Aug. 10, 1919 1,654,646 Hartwlg Jan. 3, 1928 1,798,691 MacNeill Mar. 31, 1931 1,819,245 Jones Aug. 18, 1931 1,912,611 Widmer June 6, 1933 1,947,236 Walle Feb. 13, 1934 1,994,921 Rose Mar. 19, 1936 2,077,321 Harrison Apr. 13, 1937 2,102,284 Sandin Dec. 4, 1937 2,172,950 Anderson Sept. 12, 1939 2,343,199 Moyer Feb. 29, 1944 2,435,305 Cites-singer et a1 M073, 1949 

